1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/extensions/universalchardet/src/base/nsSJISProber.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,68 @@
1.4 +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +// for S-JIS encoding, obeserve characteristic:
1.10 +// 1, kana character (or hankaku?) often have hight frequency of appereance
1.11 +// 2, kana character often exist in group
1.12 +// 3, certain combination of kana is never used in japanese language
1.13 +
1.14 +#include "nsSJISProber.h"
1.15 +#include "nsDebug.h"
1.16 +
1.17 +void nsSJISProber::Reset(void)
1.18 +{
1.19 + mCodingSM->Reset();
1.20 + mState = eDetecting;
1.21 + mContextAnalyser.Reset(mIsPreferredLanguage);
1.22 + mDistributionAnalyser.Reset(mIsPreferredLanguage);
1.23 +}
1.24 +
1.25 +nsProbingState nsSJISProber::HandleData(const char* aBuf, uint32_t aLen)
1.26 +{
1.27 + NS_ASSERTION(aLen, "HandleData called with empty buffer");
1.28 + nsSMState codingState;
1.29 +
1.30 + for (uint32_t i = 0; i < aLen; i++)
1.31 + {
1.32 + codingState = mCodingSM->NextState(aBuf[i]);
1.33 + if (codingState == eItsMe)
1.34 + {
1.35 + mState = eFoundIt;
1.36 + break;
1.37 + }
1.38 + if (codingState == eStart)
1.39 + {
1.40 + uint32_t charLen = mCodingSM->GetCurrentCharLen();
1.41 + if (i == 0)
1.42 + {
1.43 + mLastChar[1] = aBuf[0];
1.44 + mContextAnalyser.HandleOneChar(mLastChar+2-charLen, charLen);
1.45 + mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
1.46 + }
1.47 + else
1.48 + {
1.49 + mContextAnalyser.HandleOneChar(aBuf+i+1-charLen, charLen);
1.50 + mDistributionAnalyser.HandleOneChar(aBuf+i-1, charLen);
1.51 + }
1.52 + }
1.53 + }
1.54 +
1.55 + mLastChar[0] = aBuf[aLen-1];
1.56 +
1.57 + if (mState == eDetecting)
1.58 + if (mContextAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD)
1.59 + mState = eFoundIt;
1.60 +
1.61 + return mState;
1.62 +}
1.63 +
1.64 +float nsSJISProber::GetConfidence(void)
1.65 +{
1.66 + float contxtCf = mContextAnalyser.GetConfidence();
1.67 + float distribCf = mDistributionAnalyser.GetConfidence();
1.68 +
1.69 + return (contxtCf > distribCf ? contxtCf : distribCf);
1.70 +}
1.71 +
